Although is has long been recognized that water deficit in plants can result in a redcution in protein synthesis, the detailed mechanisms behind this have nor been thoroughly elucidated. In the present study, experiments were conducted to investigate the effects of water stress on protein synthesis at both transcrip-tional and psot-transcriptional levels in spirng wheat leaves (Triticum aestivum L. cv. Longchun No.10). The results reveales that stressing wheat seedlings in -0.5MPa PEG solutions for 0.24, 48 and 72h resulted in a progressive decrease in leaf protein synthesis as reflected by the incorporation fo 3 H-Leucine into chloroplast protein. Accompanying the decrease of protein synthesis, the synthetic rate of leaf RNA, the steady state levels of cellular mPNAS and rNAS, ad well as the translatbility of poly (A)+- RNAs the steady state levels of cellular mPNAs and rNAs, as well as the translatbility of poly (A)+- RNAs decreased significantly, indicating that water stress nto only affected gent transcription and RNA accumula-tion in wheat leaves but imparied the messenger-like properties of mPNAs. Furthermore, as the loss of rRNA species mighr result in disruption of the ribosomal subunits and that of mRNAs might reduce the proportion of ribosomes organized as polyriosomes it is conceivable that water stress also affected the translational level of leaf gene expresion. Based on these results, the slowdown of protein synthesis in water-stressed wheat leavs can be attributed to both transcriptional and post-transcriptional contol mechanisms.